AST RESEARCH TECHNICAL BULLETIN TB-0169                   4-25-86


               AST-5251/12  /HAYES 2400 BAUD MODEM


When using the Hayes 2400 Modem and AST-5251/12, dialing up to an 
IBM System 38,  you need to have a specific ROM chip in the Hayes 
modem.   The ROM chip number should be 245 or 249.   To determine 
which ROM chip you have,  send an ATI command to the modem.  This 
information was provided by Hayes Technical Support.     

If  you  have any additional questions regarding the  ROM   chip, 
please contact Hayes.